Crystallizing apparatus



Jan. 22, 1935. J. WALTER CRYSTALLIZING APPARATUS Filed Nov. 20, 1931 t Y I l Ill Ill .lllll l 5 Patented Jan. 22, 1935 A r RUNITED STATES PATENT OFFICE CRYSTALLIZING APPARATUS Jacques Walter, Mulhouse-Brunstatt, France, as-

slgnor to Mines Domaniales de Potasse dAlsace, Mulhouse, France Application November 20, 1931 Serial No. 576,420

In France December 23, 1930 17 Claims. (01. 23-273) My invention relates to improvements in appa ments through crystallization are greatly diminra'tus for producing crystallization in a vacuum. ished by adopting a system of forced circulation The object of this type of apparatus is to ensure with a high rate of flow, in closed circuit, for cooling, under conditions of continuous running, each element of crystallization;

by boiling, under reduced pressure, warm con- (4) It'is possible to vary, between rest and 5 centrat'ed brine in which that lowering of tem full running, the flow received and yielded by perature causes the formation of crystals. the element of crystallization without the" latter To this effect, the brine is generally caused getting out of order; in particular; the same to' go through several crystallizing elements in output may be maintained in case of partial l0 succession. Circulation between these various obturation of the discharge pipe. of the pump,

elements is usually effected by siphoning; howthe latter running, then, at full capacity; ever, such aprocess leads to serious. difiiculties (5) The repeated passing through the boiling in the operation. In particular, the apertures zone of the same brine loaded with crystals, which for connecting the elements to one another are results from the greater rate of flow of the l5 subject to obstruction by salt deposits and, as propeller as compared with that of the element said elements are grouped in series, the stopping of crystallization, results in an increase in the. of one "means the stopping of the whole plant. volume of the grains. Moreover, said elements themselves get covered Preferred embodiments of my invention will with saline incrustations, the elimination of be hereinafter described with reference to the.

which entails special and expensive care. Finally, accompanying drawing given merely by way of 20' thelevel of the brine in the various elements exampleand in which: does not remain steady and serious inconven- Fig. l is a diagram, in'vertical section, of the iences also derive fromthis cause. crystallizing apparatus according to my inven- It'has already been suggested to produce a, tion; forced circulation between the various elements, Fig. 2 is a similar view of another embodiment 25 but 'the' apparatus constructedup to the present of my invention. j v 1 to this effect present the same defects as ordi- In the drawing, the dotted lines show the path nary apparatus without forced circulation. followed by the mother-water, while the dotand The essential characteristic of the apparatus dash lines show the passage of the brine. 3O according to my invention consistsin the branch- The hot brine, previously concentrated, is

ing ofa certain number'of crystallizing elements placed in the inflowvessel 1, which is connected to a main pipe connecting the brine inflow reto the outflow vessel 2 by a main pipe 3.v To ceiver'to the outflow receiver, each element of said main pipe are connected a certain number crystallization being provided with [a pump, or of elements of crystallization, three for instance,

propeller, which draws liquid from the main pipe namely, elements 4, 5 and 6. Pipes '7, 8 and 9 35 and discharges to the element under consideraare disposed between said elements and the main tion brine issuing partly from said elementan pipe. partly from the preceding element. Toeach element of crystallization corresponds The outlet pipe of the pump'opens either above a pump, or propeller, 10, 11 and 12 respectively,

40 the level of the brine in the element of crystal-. which draws. the brine from the main pipe be- 40 lizationgor below said level, and the capacity fore the outlet pipe of the corresponding eleof the pump is chosen greater than the maximum ment. The discharge pipes of said pumps are output of the element of crystallization. provided, at their extremities, with special noz- "The'device accordingto .my invention prezles 16, 17 and 18, which open slightly above I sents, 'amongst others, the following advantages: the level of the brine in the element under con- 45 1) In case of one of the elementsof crystalsideration. Said level corresponds to the Vaclization getting blocked, said element can be isouum existing in the upper part of said element. lated andcleaned without the operation of the Elements 4, 5 and 6 are connected, at their rest of the plant being affected in any way; upper extremities, through conduits 19, 20 and -(2) The levels are stabilized almost exactly to 21, to a vacuum pump 40,'in order that the boil- 50 the level of the overflow of the outlet vessel withing ofthe brine may take place under reduced out being influenced by the crust which 'may pressure. Valves are provided to allow of stopform on the nozzle of the discharge pipe of one ping the vacuum at will in one or more of said ,ofthe'pumps;' elements, for instance, 'when it is necessary to -(3 )'--Risks of stoppage of the pipes and eleclean them. 5

The vapours emitted by elements 4, 5, 6 are condensed in apparatus which, in the example given, work by direct contact and are designated by reference characters 22, 23 and 24 respectively. In each condenser, the vapours are met by the mother-water, which is brought through branch pipes 26, 27, 28, which are connected to a-main pipe 25; said mother-water is returnedfto said main pipe through branch pipes 29, 30, 31; main pipe 25 connects vessel 32 to outflow vessel 34 through the condenser and. it receives the mother-water through a pipe. 33.

The exhausted brine runs off through overflow 35, while the salt crystalsrun out. through pipe 36.

In the second embodiment of my invention shown in Fig. 2, the organs correspond to those shown in Fig. 1, being designated bythe same, Discharge pipes 13, 14 and reference numbers. v 15 open within the brine contained in elements 4, hand 6, at a shortv distance below the free.

surface of theliquid'.

It'should be noted that the height to which the brine is conveyed is not very great and corresponds to a rather small consumption of energy. In the embodiment according to which injection takes place from the top (Fig. 1), it isequal to the difierence of level between the nozzle and the liquid situated below, increased by the loss of jhead in the circuit. In the embodiment according to which the feed takes place from the bottom (Fig. 2), the manometrical height to be won is onlyequal to, the loss, of head in the circuit. However, in order to insure a constant flow, even in the case of an abnormal resistance,

'Instead of direct contact condensers, I could.

use surface condensers, or mixed condensers, and

'cau'se'ordinary water, instead of mother-water,

to flow. through a part of the apparatus.

While I have disclosed what I deem to be preferred embodiments of, my invention, I do not wish to be limited thereto, as there might be changes made in the construction, disposition and form of the parts, with out'departing from the principle of my inventionas comprehended withinthe scopeof the appended claims.

Inthe following claims I have usedtheword circuit to designate the series of pipes and apparatus through which brine withdrawn from main pipe 3 is caused to flow before being fed back to said main pipe. For instance, such a circuit consists of pipe 13, nozzle 16, a portion of apparatus 4 and ,pipe '7. I have also used the expression connected in parallel with said main pipe, by analogy with the electrical term, to,

state that all these; circuits are independently conn'ected with said main pipe and are not in series with one another.

What I claim is: 1. A crystallizing apparatus of the type decomprises, a part of said crystallizing elements, one of these two pipes, a portion of the main pipe, and the other one of the two pipes, a pump in said circuit for causing the brine to flow thereof to said main pipe, said outlet pipe opening into said main pipe at a certain distance, in the direction of the outlet tank, from the point at which the corresponding inlet pipe branches off from the main pipe, a pump in each inlet pipe; for, discharging liquid from the main pipe intothe corresponding crystallizing. element, andlmeans. for producing a vacuum in each of said crystallizing. elements. 3 A crystallizing. apparatus. accordingv to claim 2, further comprising a nozzle at the, upper end. of each inlet. pipe located abovesthelevel of the hot brine in said ,element.

4. A crystallizingapparatus .accordingto claim;

2, in which each inlet pipe, opens into 131162002116 spending crystallizing elementbelow-t'ne level of.

the brine in said element. v

5. A crystallizing, apparatus according-to claim 2, in which the capacity of each pump is chosensubstantially greater than themaximum output. 35;.

of the corresponding. crystallizingelementr 6. A crystallizing apparatus according to claim 2, in which. the crystallizing elements. consist of" upright vessels, said apparatus further comprisingF a condenser at the upper end of eachof saidvessels.

for, condensing. the ,vapours issuingfrom: the hot brine.

7; A crystallizing, apparatus according to claim- 2, in, which the crystallizing elements consist; of

uprightvessels, saidl apparatus further comprising a direct contact condenser inthe upper endof each. of said vessels, and means. iorfeeding saidmotherwater to saidcondensen.

8. A vacuum crystallizing apparatus of thetype said main pipe, liquid propelling: means, for cans-.-

ingv thebrine to circulate throughsaid circuits, and means for ,applyinga vacuumto aportion of each of saidcircuitsfor.evaporating the brine;

9. A vacuum'cr'ystallizing apparatus of the typedescribed, which comprises in combination, a main pipe, means for causingv brine tov flow continuously through saidmain pipe, a plurality, of separate cir-r cuits forthe brineconnected in parallelwith said main pipe, liquid propelling means iforcausing the brine to circulate through said circuits, I vacuum producingmeans, and means forconnectinga par.- tion of each of. said-circuits in parallel with said vacuum producing means. v

10. A vacuum. crystallizing apparatus of the type described, which comprises in combination,

a main pipe, means for-rcausingprineto flow continuouslythrough said mainpipe, aplnrality of separate circuits for the brine connected in: pare allel. with said main pipe-liquidpropelling-means: for causing the brine to circulate through said.cir-;.

cuits, condensing means in each of said circuits-.21.

main for feeding refrigerating liquid to all of said condensing means, vacuum producing means, and means for connecting a portion of each of said circuits in parallel with said vacuum producing means 11. A vacuum crystallizing apparatus of the type described, which comprises in combination, a main pipe, means for causing brine to flow continuously through said pipe, a plurality of separate circuits for the brine connected in parallel with said main pipe, liquid propelling means for causing the brine to circulate through said circuits, condensing means in each of said circuits, a main for feeding refrigerating liquid to all of said condensing means, vacuum producing means, and a plurality of pipes connected in parallel with said vacuum producing means and opening each into one of said circuits respectively at a part thereof remote from the first mentioned main.

12. A vacuum crystallizing apparatus of the type described, which comprises in combination, a main pipe, means for causing brine to flow continuously through said pipe, a plurality of separate circuits for the brine connected in parallel with said main pip 8.- crystallizing vessel in each of said circuits, liquid propelling means for causing the brine to circulate through said circuits, a condenser in the upper part of each of said vessels for condensing the vapours produced therein, another main pipe, means for causing mother water to flow continuously through said last mentioned main pipe, a plurality of separate circuits connected in parallel with the last mentioned main pipe, each of the last mentioned circuits being arranged to feed mother water as a refrigerating liquid to each of said condensers respectively, vacuum producing means, and a plurality of pipes connected in parallel with the vacuum producing means and opening each into the upper part of each of said vessels respectively.

13. A vacuum crystallizing apparatus of the type described, which comprises in combination, an inlet tank for the hot brine, an outlet tank, a main pipe for connecting the inlet tank to the outlet tank in such manner that brine is caused to flow continuously through said main pipe, a plurality of separate circuits for the brine connected in parallel with said main pipe, pumping means in each of said circuits for circulating brine from said main pipe through said circuit, and means for applying a vacuum to a portion of each of said circuits for evaporating the brine.

14. A vacuum crystallizing apparatus of the type described, which comprises in combination, an inlet tank for the hot brine, an outlet tank, a main pipe for connecting the inlet tank to the outlet tank in such manner that brine is caused to flow continuously through said main pipe, a plurality of separate circuits for the brine connected in parallel with said main pipe, pumping means in each of said circuits for circulating brine from said main pipe through said circuit, vacuum producing means, and means for connecting a portion of each of said circuits in parallel with said vacuum producing means.

15. A vacuum crystallizing apparatus of the type described, which comprises in combination, an inlet tank for the hot brine, an outlet tank, a main pipe for connecting the inlet tank to the outlet tank in such manner as to cause brine to flow continuously through said main pipe, a plurality of separate circuits for the brine connected in parallel with said main pipe, a pump in each of said circuits for causing brine from said main pipe to circulate through said circuit, condensing means in each of said circuits, a main for feeding refrigerating liquid to all of said condensing means, a vacuum pump, and means for connecting a portion of said circuits in parallel with said vacuum pump.

16. A vacuum crystallizing apparatus of the type described, which comprises in combination, an inlet tank for hot brine, an outlet tank, a main pipe for connecting the inlet tank to the outlet tank in such manner as to cause brine to flow continuously through said main pipe, a plurality of separate circuits for the brine connected in parallel with said main pipe, a pump in each of said circuits for causing the brine from said main pipe to circulate through said circuit, condensing means in each of said circuits, a main for feeding refrigerating liquid to all of said condensing means, a vacuum pump, and a plurality of pipes connected in parallel with said vacuum pump and opening each into one of said circuits respectively at a part thereof remote from the first mentioned main pipe.

17. A vacuum crystallizing apparatus of the type described, which comprises in combination, an inlet tank for hot brine, an outlet tank, a main pipe for connecting the inlet tank to the outlet tank in such manner as to cause brine to flow continuously through said main pipe, a plurality of separate circuits for the brine connected in parallel with said main pipe, a pump in each of said circuits for causing brine from said main pipe to circulate through said circuit, a crystallizing vessel in each of said circuits, a condenser in the upper part of each of said vessels for condensing the vapours produced therein, another main pipe, means for causing mother water to flow continuously through the last mentioned main pipe, a plurality of separate circuits connected in parallel with the last mentioned main pipe, each of the last mentioned circuits being arranged to feed mother water as a refrigerating liquid to each of said condensers respectively, a vacuum pump, and a plurality of pipes connected in parallel with the vacuum pump and opening each into the upper part of each of said vessels respectively.

JACQUES WALTER. 

